On February 20, 1915, thousands crowded into the newly opened Panama Pacific International Exposition in San Francisco, CA. The exposition commemorated the completion of the Panama Canal as well as the 400th anniversary of Vasco Núñez de Balboa's journey across the Isthmus of Panama to the Pacific Ocean. Coming less than a decade after a devastating earthquake and fire in San Francisco, the exposition inspired residents and improved the city's struggling economy. The exposition grounds stretched across 635 acres, with buildings to celebrate the achievements of 35 states and 32 foreign nations. Washington state presented exhibits in its own building and participated in other themed exhibits throughout the exposition.

From 1915, San Diego hosted the Panama-California Exposition, which in 1916 was transformed into the Panama-California International Exposition. The Washington Building represented Washington state in 1915, but was renamed and repurposed in 1916 as the Palace of Mines.